For instructional films to be effective teaching device, testing based on their subject material must be devised and used. Serial Multiple Discrimination Teaching Examinations (Teaching Tests or TT's) have been so used in an introductory psychology course attended by 5,000 students in the last five years. Since these tests have a low chance factor (the probability of getting a single question correct by guessing can be as low as 1/6,250), students do not guess. They study instead, and many of them have made perfect scores (40 consecutive errorless questions). Studies have shown that students taught by these examinations earn a higher proportion of correct answers and have a wider range of scores than those taught by other objective exams; they also scored above the mean on new exams over comparable material which were prepared by professors at other universities; and item analyses have consistently shown larger discrimination indices and higher internal consistency coefficients for TT's than for True False or Multiple Choice questions. (MF)